Multipost lift



|. v. Kg HOTT 2,057,335

MULTIPOST LIFT Filed Aug. .15, i935 4 sheets-sheet 1 Nw, NN. nw f -m na.

V oci. 13, 1936.

IMI: |L F|.1

` his ATaHA/Ex l. v.K. HoTr` .MULTIPOST LIFT Filed Aug. 15, 1935 Oct.13, 1936.

4 Sheets-Sheet 2 /NVEN TDR; /a/v V. K. HU 7' 7.'

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Oct- 13, ,1936. l. v. K, HOTT MULTIPOSTLIFT Filed Aug. l5, 1935sheets-sheet s in... w N V2 u MN/N m NN ,m/

h/FATTNEK l. V. K. HOTT MULTIPOST LIFT Oct. 13, 1936.

Filed Aug. 15, 1935 4 Sheets-Sheet 4 lllllllkl /7/5 A TTU/7N: )i

Patented 13. .1.936 l UNITED "STATES: PATENT] ori-"ics 1 I 2.051.835 v l.limiueezien nume 1s. 198s, sensi No. sans inchino (CLzu-ssy i.

"rms invention relates to a multi-pest 1in and is designed primarily forelevating motor driven ')vehicles to permit access to be had to theunderneath `parts thereof for servicing. vWhen the 5 vehicle is locatedci! center on-a multi-post lift or when the vehicleis of greater weightat one end than at the other the load is unenually distributed between'the lifting elements and that lifting velement having the lighter loadwill move )o a greater distance than the lifting element hav-' ing theheavier load which results in the tilting of the load supportingstructure. If unrestrained the tilting of the load support will continueuntil it has reached an inclination which is dangerous.

"m Cne object of the present invention is to provide a fluid operatedmulti-post lift' in which the delivery of uid to the liftingv elementswill be automatically controlled to cause these lifting elements to movesubstantially equal distances,

zo therebyv preventing any considerable tilting of.

` the load supportingstructure.

A further object of the invention-is to provide such a lift in which theflow of iluid to the lifting elements will be directly controlledby thef., initial tilting of the load supporting structure.v

' A further object of the invention isto provide such a lift in whichthe exhaust of the fluid from the cylinders `will also be controlled sothat the load supporting structure: will be held against m' substantialtilting movement during the lowering o character above mentioned whichvcan beeasily installed on existing lifts Without substantial4modification` thereof. f

Other objectsv of the inventionmay appear as the mechanism is describedin detail;v

. 4;5 g In the accompanying drawings'Fig. 1 isa side elevation of amulti-post lift embodying .my invention, with the lower portions o! thecylinders l broken away ;v Fig. 2 is a transverse section taken on thelinel-l of Fig.` 1; Fig. 3 is a transverse section takin'i on the linel--3 of Fig. 1; Fig. 4 is aside elevation, of the controlling mechanism,partly in section; Fig. 5 is a diagrammatic illustration showing thelseveral conduits and their. controlling valves: Figi is a horizontalsection p .'55 `taken on the-line 6--6 of Fig.- 4; Fig. 11s a tran-J1Aare 'here shown as mounted in. guideways lfornied betweenathe verticalwebs of the rails and pro.-

verse section .taken on the line 'I-l of Fig. U: Fig. 8 is a" transversesection taken on the line H of Fig. 6; Fig. 9 is a transversesectiontaken onthe line l-S of Fig. 6; Fig. 10 is a transverse section taken onthe line I0--I0 of Fig. 6; Fig. 11 5 is a longitudinal section taken onthe line lI--li of Fig. 6; Fig. 12 is a longitudinal section taken onthe line l2|2 of Fig. 6.; and Fig. 13 is'a longitudinal section takenonthe line I3-I3 of Fig. 6.

fIn these drawings I have illustrated che em- 10 bodiment of myinvention and `have shown the, saine as' applied to a two post iluidoperated lift, that is, a lift having a singlev lifting element at eachend thereof. I have also shown the cylin- -ders of the lifting elementsas sunk in the ground 15 but itiwill be understood that this particularem- [bcdiment has been chosen for the purpose of illustration onlyl andthat the invention may take various forms and may be applied toiiuidoper- 1 ated lifts of various kinds having two or more "m liftingelements. v

lIn ythat embodiment of the invention here i1. lustrated the liftcomprises two posts or lifting elements i! and i6 each of whichcomprises ay vertical cylinder I'I which, in the present in-- g5 stance,is 'sunk inthe lground, and a ram I8 `mounted for longitudinalmoviientin the cylin v e of Vany suitable character is secured to theupper ends of the rams 1B, preferably in such a manner that it 30 5 mayhave tilting movement with relation thereto.

der. A load supporting struct The particular lift here shown is'of thefree wheelv type and the load supporting structure comprises a pair ofparallel rails I9 supported near their ends'on therespective rams I8.The 35 rails are here shown as H-beams and are thus providedwithchannels -onn'the inner sides thereof, andplates are mounted in theVcl'iannels of the respective rails adjacent to each ram. The plates 20,adjacent to the lifting element I6, are 40 rigidly secured to the rails,as by welding, andv are provided withl bearings 2l, here shown asinw'ardly extending bosses. Rigidly secured'to the upper end of the ramof the liftingqelement i6 is l a crossmember 22 having parts. Vsuch asthe ends 45 of a shaft 23, rotatably mounted in the bearings 2i. Mountedin the channels of vthe rails il ade. jacent to\ the lifting-.element l5are plates I 2l" which are. slidable lengthwisenof the-rails andiections 25 spaced from said ,weh These plates are also provided withbearings, vas shown at ,28,v

Aand a'. cross member 21 is .rigidly .secure-dto the 55 adjacent ram andprovided with parts, such as the ends of a shaft 28, rotatably mountedin the bearings. Thus the load supporting structure is movable at oneend about a fixed axis and at'its other end about an axis which ismovable lengthwise thereof to compensate for the increased distancebetween the upper'ends of the rams when the latter are at differentheights.

Connected with the'cylinders of the respective lifting elements areconduits 29 and 38 which are adapted to be connected with a suitablesource 'of supply for fluid under pressure, Vsuch as a reservoir 3|adapted to contain oil under air pressure, air under pressure beingdelivered to the reservoir through a pipe 32 and exhausted therefromthrough o. pipe 33, and the twol pipes being controlled by separatevalves 34 in a well known manner.- A pipe 35 leads from`the reservoir 3|and is connected with the conduits 29 and 30 through suitablecontrolling mechanismvand is also provided with a cut-off valve 36.

The controlling mechanism comprises valves interposed between thereservoir pipe 35 and the conduits 29 and 30 and adapted to becontrolled in accordance with the angular position of the loadsupporting structure I9 so that a slight initial tilting ofthe loadsupporting structure will reduce 'the flow of fluid `to the higher ramand thus retard its movement and prevent the further tilting of the loadsupporting structure. Referring rst to the diagrammatic illustration ofFig. 5,'lt will be noted that the conduit 29, which is connected withthe lifting element I6, comprises two branches 31 and 38 and that theconduit 30 which is connected with the lifting e'lement i5 alsocomprises two branches 40 and 4|-, The branch 31 of conduit. isconnected at that end remote from its lifting element with a mainconduit 42 which is connected with the reservoir pipe 35. Mounted inthis conduit is a. valve 43 which is normally open to permit the flow offluid therethrough and which is provided with an actuating device, suchas the valve stem 44. Interposed in the conduit 31, between the valve 43and the main conduit 42, is a check valve 45 arranged to permit fluid toflow from the main conduit to the valve but to prevent fluid fromflowing from the valve 43 back to the main conduit. The branch 38 ofconduit 29 extends beyond the branch 31 and is connected with the mainconduit 42. vA check valve 46 in the conduit 38 permits the flow ofiiuid from the conduit 29 to the main conduit but prevents the flow offluid from the main conduit to the conduit 29. The flow of fluid throughthe conduit 38 is controlled by a valve 41 having an actuating device orstem 48, this valve also being normally open. The branch 40 of conduit30 is connected with the main conduit 42 and is provided with a normallyopen controlling valve 49, having an actuating device or stem 50, andwith a check valve 5| to prevent fluid from flowing from the conduit 30to the main conduit. The branch 4| of the conduit 38 extends to a pointadjacent to the inner end of the conduit 31 and is connected with themain conduit 42 and is also provided with a check valve 52 to preventfluid from flowing from the main conduit to the conduit 30 and with anormally open controlling valve 53 having an actuating device 54.During. the elevation of the load iiuid under pressure flows through thereservoir pipe 35, main conduit 42 and through the branch conduits 31and 40 tothe conduits 29 and 30 which are connected respectively withthe cylinders of lifting elements I6 and l5. The valves 43 and 49 arenormally open so that fluid flows i'n substantially equal quantities tothe two I lifting elements and when these. lifting elements carrysubstantially equal loads they will move upwardly in unison and the loadsupporting struc- 'ture will remain substantially horizontal, or if,

as in some cases, lt is normally supported at a slight inclination itwill be retained at the predetermined angle. When the load is beinglowered the fluid will ow from the cylinders, under pressure of theload, through conduits 29and 38 and branches 39 and 4| to the mainconduit l42 and thence back to the reservoir. The valves 41 and 53 arelikewise normally open and when the l lifting elements are equallyloaded they will move downwardly in unison.

In order to cause the lifting elements to move at substantially the samespeed and thus move substantially the same distances, therebymaintaining the load supporting structure in its horizontal position, Ihave provided means for automaticallyactuating the controlling valves lnthe several branch conduits. This means is of such a character thatwhen, during the elevation of the load, the load supporting structure istilted the controlling valve in the branch conduit leading to thelifting element supporting the higher end of the load supportingstructure will be closed or partially closed to restrict the supply offluid to that lifting element, thereby retarding the movement of thatend of the load supporting structure and preventing the further tiltingthereof. The restriction of the flow of fluid to one lifting elementwill permit a greater flow of fluid to the other lifting element, thusproviding the latter with additional power to lift the heavier loadthereon. If, during the lowering of theload, the supporting structuretilts the valve in the branch conduit leading to the lifting elementwhich supports the lower end of the load supporting structure will beclosed or partly closed to restrict the escape of fluid from thatlifting element and thus retard its downward movement.

-The means for actuating these valves may take various forms but itpreferably comprises an actuating member 55, here shown in the form of atubular rod, which is so connected with the load supporting structurethat it will be moved by the tilting movement of that structure.Preferably it'is rigidly secured to the load supporting structure sothat it will move with and will be tilted simultaneously with thetilting of the load supporting structure. In the present instance, theactuating device 55 is provided at its upper end with a transverse head56 which is pivotally connected at 51 with a supporting member 58 whichis rigidly but adjustably secured to and extends laterally from thecross member 22 which connects the rails to lifting element I6. Screws59 which are threaded in the supporting member 58 engage the head 56 onopposite sides of its axis so as to establish a rigid connection betweenthe actuating rod 55 and the load supporting structure, but theadjustment of the screws will enable the rod to be positioned atdifferent angles with relation to the load supporting structure, as, forexample, when the latter is normally supported at an angle. Theactuating member 55 `extends downwardly into such relation to the valveactuating devices that its movement in one direction will operate thesupply valve for the conduit leading to one lifting element and theexhaust valve in the conduit leading from the other lifting element.While both valves are operated only one 75 y mousse' valve is effectivebecause the check valves prevent l the flow of fluid through the exhaustbranch during the lifting of the load and through the supply branchduring the lowering of theload. Inthe present apparatus the controllingvalves are arranged in pairs,`\the' supply valve 43 and the exhaust4valve 53 being arranged on one side of .the actuating member 55 andthesupply valve 49 and the exhaust valve 41 being arranged on the otherside of the actuating member.

nected one'tothe other by cross members 69 which lie closer to and may,if desired,- contact,

.with the respective sides of theA actuating mem- `-ber close-theexhaust valve'leading from the lifting element which supports the lowercend of the load supporting structure.

Referring nowto the detail drawings illustrating the conduits and theirvalves, Figs. 6 to 13, it

- leads from the mainconduit 42 to a valve cham and this valve chamberis connected by al port 99 with a passageway 'I0 leading to the conduitI9.

will b'e observed that these parts are formed in y a unitary structurehaving at its respectiveends parts 6i and 62 with which the conduits 29and 30 `are connected, these: parts being herein referred to as valvecasings. The severalparts of the unitary structure may be rigidlyconnected ,one with the other in any suitable manner, as by casting thesame in one piece.. The supply branch for each conduit, 29and 39, andits valve, are in the valve casing; with which the conduit is connected,and the exhaust branch-for each of' said conduits extends tothe valvecasing with which the other conduit is connected and has its valve inthat valve casing. In the arrangement here illustrated the main conduit42 vis connected at its ends 4with the respective valve casings and isconnected betweenits ends with the reservoir pipe 35. The supplybranchconduit31, which connects the main conduit 42 with the conduitv 29isformed in the valve casing 9i, (see Figs. 6, 9,

`and 10) and. comprises a transverse passageway 63 leading from the mainlconduit 42 to a valve chamber 64 in which the supply valve 43 ismounted. 'I'his valve chamber 64 is connected by a port 65 with apassageway 66 leading to the conduit 29. Likewise'the branch 49'whichcon- "nects the main conduit 42 with the conduit 39 is formed in thevalve casing 92, (Figs. 6, 7, and 8) vand comprises a transversepassageway 61 which Aber 99 in which the supply valve 49 is mounted Thesupply valves43 and 49 are held normally in their open positions byvsprings 9| and the checle valves 5I and 52 are interpovsedbetween there- -lspect'ive transverse passageways the main conduit 42.

i Thereturnor exhaust conduit 99 which con?V nects the conduit 29 withthe main conduit 42 comprises a transverse passageway 1|, Yin valve'casing 6i, (Figs. 9'and `1-0), which is connected'- with the passagewayB9 leading to the conduit 29 and this transverse passagewayis connectedby the' longitudinal portion of the branch .with-a second transversepassageway 12, in valve casing 92, (Figs. 6 and 12. w`hich leads to avalve cham- ,ber-13 in which the exhaust valve 41 is mounted, and thisvalve chamber is connected by a port 14 r The actuating devices for thevalves of each pair are conactuating member.

Bland and 3 (Fig.4 8) ywith transverse .passageway I5 extend- .ins`above-the valve chamber 99 and connected through the ch'eck valve 49with the main conduit 42. 'Ihe return or exhaust branch'll whichyconnects the conduit 39 with themain conduit -42 comprises a transversepassageway 16, in valve casing 62, (Figs. 7 and 8) which is connected atone end with the passageway 19 leading to theA conduit 39 and isconnected by the-'longitudinal portion of thev branch with a" transverseconduit 11, in valve casing 6|, (Figs. 6 and 9), which leads to a valvechamber' 18 in which the .exhaust valve 53 is mounted and this valvechamber 18' is connected by a port 19 (Fig. 10) with a transversepassageway 91|` leading through the check valve '45 t to the mainconduit 42., 'I'he exhaust valves 41 and 53 are held normally in theiropenv positions by springs 9|. I

-The structure vwhichv includes the controlling valves and theirconduits may be arranged in any suitable position below the loadsupporting struc-- ture andpreierably it is enclosed within 4ahousing.

82 which is sunkin the ground adjacent to one of the lifting elementsand-the actuating member 55 is so mountedo'n the load supportingstructure .that it will extend through the housing between. .the twopairs of valve actuating-members, an

opening 83 being provided inC the ground beneath the housing to receivethe-lower portion of the While I have shown and described one embodimentof my'invention I wish it to be understood that I do not desire to belimited to the details thereof as various modifications may occur tol aperson skilled in the art.

Having now rmly'described my inventan, what I claim as new and desire tosecure by Letters Pat-' I ent, is:

1. In a multi-post lift comprising a plurality of .uid operated elementsand a load supporting structure carried by said lifting elements andcapable of `tilting movement with relation thereto, means for connectingthe respective rlifting elements with a source of uid supply, eachconnecting means comprising a valve to control the i ow of fluid to itslifting element and a second .valve to control the return of jthe fluidfrom its lifting element to said source of supply, and means controlledby the tilting movement of said load supporting structure in onedirection to actuate the supply valve for .one lifting element and theexhaust valve for another lifting element.

2. ,In a multi-post 'lift comprising a plurality of fluid operatedlifting elements and a load supy porting structure carried by saidlifting elements,

and 'capable of tilting movement with relation thereto, an actuatingmember rigidly connected with'said load supporting structure andoperable l.'

.by the tilting movementl thereof, and means for connecting therespective lifting elements with aV source of huid supply,l eachconnecting means 'having a valve arranged on one side of said actuatingmembery and actuated by the movement thereof in one direction .tocontrol-the vflow of duid to its lifting element `and having 'a'second ingmember and actuated by the movement thereof inthe other direction tocontrol the flow of iiuid from its lifting element to said source of supply.

3.l In a multi-post lift comprising 'a plurality of fluid operatedlifting elements and a load supporting strncture carried by said liftingelementsl and capable of tilting movement with relationl thereto, a.lmain conduitl connected with a source- .65 valve arranged on the other'side of said actuattion thereby, one. valve of each pair being arofsupply of fluid under pressure, means for delivering iiuid from saidmain conduit to each: lifting element to elevate said load supportingstruc' ture and for returning fluid from each lifting element to saidmain conduit to lower-said load supporting structure, and meanscontrolled by. the tilting movement of said load supporting structure inone direction 'to restrict t'heisupply of lfluid to one of said liftingelements whilefsaid structure is being elevated and to restrict thereturn of fluid from another of said liftingelements to said mainconduit While said structure is being lowered. i A 4. In a multi-postlift comprising a plurality of fluid operated lifting elements andaloadsupporting structure carried by said lifting elements and capableof tilting movement with relation thereto, a main conduit connected witha source of supply of fluid under `pressure, a supply conduit and areturn conduit connecting each lifting element with said main conduit,valves in r,said supply conduits and said return conduits, `and meansactuated by the tilting of said load supporting structure in onedirection to actuate the valves in the supply conduit of one liftingelement and in the return conduit of another lifting element.

5. In a multi-post lift comprising a plurality of fluid operated liftingelements and a load' supporting structure carried by said liftingelements and capable of tilting movement with relation thereto, a mainconduit connected with a source of supply of fluid under pressure, asupply conduit and a return conduit connecting each lifting element witha main conduit, valves in said supply conduits and said return conduits,yieldable means to retain said valves normally in their open positions,and means actuated by the tilting of said load supporting structure inone direction to close the valves in the supply conduit of one liftingelement and in the return conduit of another lifting element while thevalves in the other conduits remain open.

. 6. In a multi-post lift, a plurality of fluid operated liftingelements, a load supporting structure carried by said' lifting elementsand capable of tilting movement with relation thereto, an actuatingmember connected with said load supporting structure and operable by thetilting movement thereof, conduits connected with the respective liftingelements, each conduit comprising a branch to supply fluid to itslifting element and a second branch to exhaust the fluid from itslifting element, and two pairs of valves mounted on opposite sides ofsaid actuating memberfor operaranged in the supply branch of the conduitconnected with one of said lifting elements and the other valve of thatpair being arranged in the exhaust branch of the conduit connected withAthe other lifting element.

7. In a multi-post lift, a plurality of uidopera ated lifting elements,a load supporting structure carried by said lifting elements landIcapable of tilting movement with relation thereto, an actuating memberconnected with said lload supporting structure andoperable by thetilting movement thereof, 'a main conduit connected with a source offluid supply, two pairs of branch conduits to connect said main conduitwith the respective lifting elements, each pair comprising a supplybranch and an exhaust branch, check valves in the respective branchconduits to prevent the simultaneous Viiow of fluid through the twobranches of either pair, controlling valves in the aosasss`respectivebranch conduits, means to hold said controlling valvesnormally in-their open positions, and means actuated by said actuatingmember to move said controlling valves toward their closedpositions,.said controlling valves and the means for movingzthe samebeing so, arranged with relationto said actuating member that themovement of said actuating member in one direction will operate thevalve in the supply branch leading to one lifting element and thevalvein the exhaust branch leading to another'lifting element, and themovement -of said actuating member in the other direction vwill operatethe valve in the supply branch leading tothe last mentioned liftingelement and the valve in the exhaust branch leading to the firstmentioned lifting element.

8. Ina multi-post lift, fluid operated lifting elements near therespective ends of said lift, a load supporting structure carried bysaid lifting elements ,andcapable of tilting movement, conduits leadingto the respective lifting elements, a main conduit connected with asource of fluid supply. two 4valve casings each having a supply valvechamber and an exhaust valve chamber and having passageways connectingboth valve chambers of the respective valve casings with said mainconduit and' connecting said supply valve chambers with the/conduitsleading to the respective lifting elements, and other passagewaysconnecting the exhaust valve chamber of each casing with the conduitleading from the supply valve chamber of the other casing to thecorresponding lifting element, a valve in each valve chamber, and meanscontrolled by the tilting movement of said load supporting structure toselectively actuate said valves.

9. In a multi-post lift, lifting elements arranged near the respectiveends of said lift and each comprising a vertical cylinder sunk in theground and a ram mounted' for longitudinal movement in said cylindenaload supporting structure mounted on said rams for tilting movement withrelation thereto, a downwardly extending rod rigidly secured to saidload supporting structure, conduits connecting the respectivecylinderswith a source of fluid supply, each conduit comprising a branch tosupply fluid to its cylinder and a second branch to return fluid fromits cylinder to said source of supply, means for preventing thesimultaneous flaw of uid through both branches of either conduit, 4avalve in each branch of each conduit, and actuating devices for saidvalves so arranged with relation to said rod that the tilting of saidrod in one direction will cause the ,same to operate the valve in thesupply branch of one conduit and the valve in the exhaust branch of 'theother conduit, and the tilting of said rod in the other direction willcause the same to operate the valve in the supply branch of the lastmentioned conduit and' the valve in the exhaust branch of the firstmentioned conduit.

10. In a' multi-post lift, fluid operated lifting elements near therespective ends of said lift, parallel rails supported by said liftingelements `and having longitudinal channels, plates rigidly mounted insaid channels adjacent to one of said fluid supply, valves in therespective conduits.

and actuating devices'for said valves -so arrangedv with relation' tosaid actuating member that the movement imparted to said actuatingmember by the tilting of said load Supporting structure in one'direction will operate a valve in one of said conduits and movementimparted to said actuating member by the tilting of said load supportingstructure in the other direction will operate a valve in the other ofsaid conduits.

ION VON KERT HOTT.

